Antegrade cardioplegia catheter and method

ABSTRACT

A cardioplegia catheter is configured to extend into the ascending aorta with a proximal portion of the shaft extending into a left chamber of the heart through a aortic valve and out of the heart through a penetration in a wall thereof. The cardioplegia catheter has an occlusion member configured to occlude the ascending aorta between the brachiocephalic artery and the coronary ostia. An arterial return cannula delivers oxygenated blood to the arterial system downstream of the occlusion member, while cardioplegic fluid is delivered through a lumen in the cardioplegia catheter upstream of the occlusion member to induce cardioplegic arrest.

CROSS-REFERENCE TO RELATED APPLICATION

This application is continuation of U.S. patent application Ser. No.08/839,189, filed Apr. 23, 1997, now issued as U.S. Pat. No. 6,090,086,the complete disclosure of which is incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates generally to catheters for use in medicalprocedures, and more specifically to a catheter system for inducingcardioplegic arrest and maintaining circulation of blood.

BACKGROUND OF THE INVENTION

Cardiac surgery is conventionally performed with the patient's heartstopped and with circulation of blood maintained by extracorporealcardiopulmonary bypass, a state known as cardioplegic arrest.Cardioplegic arrest conventionally requires the creation of a largeincision in the chest, known as a sternotomy or thoracotomy, to exposethe heart and great vessels of the thorax. Through this large incision,a steel clamp, called a cross-clamp, is placed around the aorta betweenthe coronary arteries, which deliver blood to the heart muscle, and thebrachiocephalic artery, which delivers blood to the head and neck. Theclamp is closed so as to collapse the aorta, thereby partitioning theheart and coronary circulation from the remainder of the arterial systemdownstream of the cross-clamp. Pharmaceutical agents may then bedelivered into the coronary arteries or aorta upstream of the cross-lampso as to arrest cardiac function. Circulation of blood is maintainedthroughout the body by placing a venous drainage cannula in a major veinor in the right side of the heart to withdraw venous blood, routing theblood to an extracorporeal oxygenator, and pumping the blood back intothe arterial system through a cannula positioned in a major artery,typically in the aorta just downstream of the cross-clamp.

While cardiopulmonary bypass with cardioplegic arrest is currently thegold standard for performing most cardiac surgical procedures,conventional techniques suffer from several drawbacks. Important amongthese are the high degree of pain and trauma, risk of complications andlong recovery time which result from median sternotomy and other typesof gross thoracotomy. Furthermore, the use of a cross-clamp on acalcified or otherwise diseased aorta can produce serious complicationssuch as embolization of plaque, potentially leading to stroke and otherneurological problems.

In U.S. Reissue Pat. No. Re 35,352 to Peters, which is assigned to theassignee of the present invention and is hereby incorporated herein byreference, it is suggested that the use of a cross-clamp to achievecardioplegic arrest could be avoided through the use of an endovascularballoon occlusion catheter positioned from a femoral artery into theascending aorta. A balloon at the distal tip of the occlusion cathetercan be expanded to occlude the aorta between the coronary arteries andbrachiocephalic artery, and cardioplegic fluid then delivered through alumen in the catheter into the aorta upstream of the balloon so as toarrest the heart. Cardiopulmonary bypass is established by placingarterial and venous cannulae in a femoral artery and femoral vein,respectfully, and routing the patient's blood through an extracorporealoxygenator and pump.

While the endovascular technique proposed in the Peters patent is usefulin many cardiac surgeries to avoid the need for median sternotomy andaortic cross-clamping, the technique can have disadvantages in somesituations. For example, in patients with severe peripheral vasculardisease, the balloon occlusion catheter may be difficult to introduceinto the femoral arteries and to advance transluminally into theascending aorta.

Another technique for inducing cardioplegic arrest without the use anaortic cross-clamp is proposed in U.S. Pat. No. 5,312,344 to Grinfeld.This technique involves the placement of a balloon occlusion catheterinto the ascending aorta directly through a puncture in the aortic wall.The balloon occlusion catheter has an occlusion balloon at its distaltip which is used to occlude the aorta between the coronaries and thebrachiocephalic artery. The catheter further includes an arterial returnlumen through which blood may be delivered into the aorta downstream ofthe balloon, eliminating the need for a separate arterial returncannula.

The Grinfeld technique, however, also suffers from a variety ofdisadvantages. First, because the catheter is introduced through theascending aortic wall, the technique requires dissection and retractionof the various tissues surrounding the ascending aorta to expose thevessel. This is particularly difficult if the procedure is to beperformed minimally-invasively through trocars or small incisions,without a median sternotomy or other gross thoracotomy. In addition,many patients who receive cardiac surgery have some degree of aorticcalcification or other aortic disease. In such patients, it isundesirable to puncture the aortic wall with a catheter as taught byGrinfeld, as this could embolize plaque, initiate or aggravate an aorticdissection, or create other problems. Finally, in Grinfeld's technique,because oxygenated blood is returned to the arterial system through alumen within the aortic occlusion catheter itself, should the surgeondesire to remove the occlusion balloon from the aorta due to a balloonpuncture or other problem, the patient must first be re-warmed andweaned from extracorporeal cardiopulmonary bypass before the balloon canbe removed, lengthening the procedure considerably.

What is needed therefore, are devices and methods for inducingcardioplegic arrest and maintaining circulation of oxygenated bloodwhich do not require median sternotomy or other gross thoracotomy andwhich eliminate the need for aortic cross-clamping, but which overcomethe disadvantages of known endovascular balloon occlusion devices. Thedevices and methods should be useful in patients having severeperipheral vascular disease as well as in those having-aorticcalcification, without creating a high risk of embolization, aorticdissection, or other complications. The devices and methods shouldfurther avoid the need to directly access the aorta and the associatedneed to dissect and retract the surrounding tissues. Moreover, thedevices and methods should optionally allow occlusion of the aorta to bediscontinued and any occlusion device to be removed from and replaced inthe aorta without weaning the patient from cardiopulmonary bypass.

SUMMARY OF THE INVENTION

The invention provides catheter systems and methods for inducingcardioplegic arrest that overcome many of the disadvantages of knowntechniques. The systems and methods of the invention facilitateendovascular occlusion of the ascending aorta, delivery of cardioplegicfluid, venting the aortic root, monitoring of aortic root pressure, andcirculation of oxygenated blood through the patient's arterial systemwithout the need for median sternotomy, aortic cross-clamping, or directaccess to or puncture of the aorta. If peripheral vascular disease makesendovascular access through peripheral vessels difficult, the systemsand methods of the invention may be utilized without such access.Optionally, the systems and methods of the invention further allowaortic occlusion to be discontinued and occlusion devices to be removedfrom the aorta without weaning the patient from cardiopulmonary bypass.

In a first embodiment, the invention provides a cardioplegia catheterfor inducing cardioplegic arrest that comprises a shaft with a distalend, a proximal end, an opening near the distal end, a port at theproximal end, and an inner lumen fluidly connecting the port and theopening. A distal portion of the shaft is configured to extend into theascending aorta with a proximal portion of the shaft extending into aleft chamber of the heart through the aortic valve and out of the heartthrough a penetration in a wall thereof. An occlusion member is mountedto the shaft distally of the opening and configured to occlude theascending aorta between the brachiocephalic artery and the coronaryostia. In a preferred embodiment, the cardioplegia catheter isconfigured to be introduced through the wall of the heart into the leftatrium, from which it is advanced through the mitral valve into the leftventricle, and through the aortic valve into the ascending aorta. Theshaft is long enough to extend out of the heart and out of the chestwhen the distal end is positioned in the ascending aorta, preferablybeing about 25-75 cm in length.

The occlusion member is preferably a balloon, and an inflation lumenextends through the shaft in communication with the interior of theballoon for delivering an inflation fluid into the balloon. Theocclusion member may alternatively be a collapsible one-way valve withone or more movable leaflets, an umbrella-like expanding membrane, orother mechanical occlusion device.

The cardioplegia catheter of the invention may further include a sealingdevice for sealing the penetration in the wall of the heart around theshaft to inhibit blood flow therethrough. The sealing device preferablycomprises a purse string suture that may be applied to the wall of theheart around the penetration. The purse string suture may then betensioned to seal the penetration around the catheter shaft.

In order to facilitate positioning the distal end of the cardioplegiacatheter in the ascending aorta from a left chamber of the heart, adistal portion of the catheter may be preshaped in an appropriate shapethat the catheter naturally assumes in an unbiased, unrestrainedcondition. For embodiments positioned via the left atrium, the shaft maybe preshaped such that the distal end is maneuverable around the sharpturn from the mitral valve toward the aortic valve. In such a shape, adistal portion of the catheter shaft is preferably disposed at an anglebetween about 20 and 90 degrees relative to a proximal portion of theshaft. In order to facilitate introduction of a cardioplegia catheterhaving such a shape, a relatively stiff obturator may be placed in aninner lumen of the catheter to straighten the shaft during introduction,the obturator being withdrawn from the catheter as it is advanced intothe aorta.

As an alternative or supplement to a preshaped shaft, the inventionfurther provides a guiding device for guiding the distal end of theshaft into the ascending aorta. In one embodiment, the guiding devicecomprises a guidewire positionable in the ascending aorta from the leftchamber of the heart. In another embodiment, the guiding devicecomprises a stylet removably positionable in a lumen within the shaft,the stylet having an end portion for shaping the shaft. The stylet mayhave a shaping mechanism for shaping the end portion, whereby anactuator at a proximal end of the stylet may be actuated so as to causethe stylet to assume a suitable shape, thereby imparting the shape tothe cardioplegia catheter. The shaping mechanism may comprise steeringwires, push rods, or other mechanisms suitable for changing the shape ofthe stylet.

In a further embodiment the guiding device comprises a flow directedcatheter positionable through a lumen in the shaft and having anexpandable member at its distal end configured to be carried by bloodflow into the ascending aorta. Once the flow-directed catheter has beenpositioned in the ascending aorta, the cardioplegia catheter may beslidably positioned over the flow-directed catheter. Alternatively, theflow directed catheter may have an inner lumen through which a guidewireis first positioned into the ascending aorta, the flow-directed catheterthen being withdrawn and the cardioplegia catheter positioned over theguidewire into the ascending aorta.

A source of cardioplegic fluid is usually connected in communicationwith the port at the proximal end of the shaft, allowing cardioplegicfluid to be delivered through the inner lumen into the ascending aortaupstream of the occlusion member to arrest the heart. Preferably, theinner lumen is configured to deliver a cardioplegic fluid containingblood at a rate of at least 150 ml/min and a pressure less than about350 mmHg, the inner lumen having a cross-sectional area of at leastabout 2.2 mm² between the port and the opening.

Arterial blood circulation may be maintained in various ways. In oneembodiment, the cardioplegia catheter includes a delivery opening distalto the occlusion member, a delivery port at the proximal end of theshaft, and a delivery lumen extending between the delivery port and thedelivery opening. The delivery lumen may be configured to provide returnof oxygenated blood to the aorta downstream of the occlusion member as asubstitute for or a supplement to a separate arterial return cannula. Asthe sole conduit for return of blood to a patient under fullcardiopulmonary bypass the delivery lumen is configured to deliver bloodat a rate of at least about 4 liters/min at a pressure no more thanabout 350 mmHg, usually having a cross-sectional area of at least about30 mm².

In alternative embodiments, return of arterial blood may be provided byone or more arterial cannulae positioned independently of thecardioplegia catheter. In one embodiment, an arterial return cannula isslidably positioned through the delivery lumen in the cardioplegiacatheter, allowing the arterial return cannula to be placed in any ofvarious positions relative to the occlusion member, and allowing theocclusion member to be withdrawn from the aorta without removing thearterial return cannula. In another embodiment, the arterial cannula isplaced in parallel with the cardioplegia catheter through the leftatrium, left ventricle and aortic valve, and the cardioplegic catheterhas an occlusion member that conforms around the cardioplegia cannula toocclude the ascending aorta. Alternatively, the arterial return cannulamay have a lumen configured to allow the cardioplegia catheter to beslidably positioned through it. The cardioplegia catheter has a bloodreturn lumen extending distally of the occlusion member and at least oneinlet port in its sidewall through which blood may enter the bloodreturn lumen from the arterial return cannula. In alternativeembodiments, an arterial return cannula is placed in a peripheral vesselselected from the femoral, iliac, subclavian or axillary artery. In aparticular embodiment, the arterial cannula is configured to extend intoor near the aortic arch from the peripheral artery, allowing arterialblood to be returned such that flow through the aorta and its branchesis in an antegrade direction.

The cardioplegia catheter of the invention preferably includes apressure monitoring device coupled to the shaft for monitoring pressurein the ascending aorta proximal to the occlusion member. Usually, apressure opening is provided in the shaft proximal to the occlusionmember, a pressure port is disposed at the proximal end of the shaft,and a pressure lumen extends between the pressure port and the pressureopening. A pressure monitoring device may be coupled to the pressureport at the proximal end of the shaft so as to measure pressure in theaortic root during the procedure.

A method of inducing cardioplegic arrest according to the inventioncomprises the steps of: forming a penetration in a wall of a leftchamber of the heart; positioning a cardioplegia catheter through thepenetration into the left chamber of the heart; forming a seal betweenthe wall of the heart and the cardioplegia catheter to inhibit leakageof blood through the penetration; advancing a distal end of thecardioplegia catheter in the direction of blood flow from the leftchamber of the heart, through the aortic valve and into the ascendingaorta; expanding an occlusion member on the cardioplegia catheter so asto occlude the ascending aorta downstream of the coronary ostia andupstream of the brachiocephalic artery; delivering cardioplegic fluidthrough the coronary vasculature to the myocardium so as to arrestcardiac function; and circulating oxygenated blood in the patient'sarterial system downstream of the occlusion member.

In a preferred embodiment, the step of circulating comprises positioningan arterial cannula in an arterial location downstream of the occlusionmember, the arterial cannula being independently positionable relativeto the occlusion member. The arterial cannula is usually positioned in aperipheral artery selected from a femoral artery, iliac artery,subclavian artery or axillary artery, the step of sealing preferablycomprises placing a purse string suture in the wall of the heart aroundthe penetration.

The step of advancing preferably comprises sliding the cardioplegiacatheter over a guiding device positioned in the left chamber of theheart and extending into the ascending aorta. The guiding device maycomprise a guidewire, flow-directed catheter, stylet, or other device asdescribed above.

The method is preferably practiced without a median sternotomy or otherform of gross thoracotomy, i.e., with the patient's sternum and ribssubstantially intact. In some cases, it may be desirable to form a smallincision between the ribs, known as a mediastinotomy ormini-thoracotomy, which in some circumstances may involve the cutting orremoval of one or more of the costal cartilages which connect the ribsto the sternum. In any event, the incision or opening formed in thepatient's chest may be as small as practicable under the circumstancesof the case, generally being smaller than the hands of the surgeon,usually having a length of less than about 8 cm, and preferably having alength of less than about 6 cm, with a width not much wider than thedistance between the ribs, e.g., about 20-30 mm. In a particularlypreferred embodiment, the cardioplegia catheter will be placed through acannula, trocar or other retractor placed within an intercostal spacebetween the ribs, and guided into the heart using long-handledthoracoscopic instruments positioned in the chest via intercostal accessports. The surgeon may visualize the interior of the chest eitherdirectly through such access ports, or using a thoracoscope and videocamera. Placement of the occlusion balloon in the ascending aorta may bevisualized using transesophageal echocardiography or fluoroscopy.

A further understanding of the nature and advantages of the inventionwill become apparent from the following detailed description taken inconjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side cross-sectional view of a cardioplegia catheteraccording to the invention.

FIG. 2 is a transverse cross-section of the cardioplegia catheter ofFIG. 1 taken along line 2—2.

FIG. 3A is a partial cross-section of a patient's heart illustrating thepositioning of the cardioplegia catheter of FIG. 1.

FIG. 3B is a schematic view of a cardiopulmonary bypass system andassociated catheters used in a patient's body in conjunction with thecardioplegia catheter of FIG. 1.

FIG. 4 is an elevational view of an outer wall of a patient's heartillustrating the placement of a purse-string suture around a penetrationtherein.

FIGS. 5-7 are partial cross-sections of a patient's heart illustratingthe introduction of the cardioplegia catheter of FIG. 1 into theascending aorta.

FIG. 8 is a side view of a cardioplegia catheter according to theinvention in a second embodiment thereof.

FIG. 9 is a transverse cross-section of the cardioplegia catheter ofFIG. 8 taken along the lines 9—9.

FIG. 10 is a partial cross-section of a patient's heart illustrating thepositioning of the cardioplegia catheter of FIG. 8.

FIGS. 11-14 are partial cross-sections of a patient's heart illustratingvarious embodiments of arterial return cannulas according to theinvention.

FIG. 15 is a side partial cross-section of a further embodiment of acardioplegia catheter system according to the invention.

FIG. 16 is a transverse cross-section of the cardioplegia cathetersystem of FIG. 15 taken along line 16—16,

FIG. 17 is a partial cross-section of a patient's heart illustrating theuse of the cardioplegia catheter system of FIG. 15.

FIG. 18 is a partial cross-section of a patient's heart illustrating afurther embodiment of a cardioplegia catheter system according to theinvention.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

Referring to FIG. 1, a first embodiment of a cardioplegia catheteraccording to the invention will be described. Cardioplegia catheter 20has a shaft 22 having a distal end 24 and a proximal end 26. Anocclusion balloon 28 is attached to shaft 22 near distal end 24 byadhesive bonding or other known technique. One or more radiopaque bandsor markers 29 are provided on shaft 22 adjacent occlusion balloon 28 topermit fluoroscopic imaging of the catheter within the aorta.

Shaft 22 has a plurality of lumens, as shown in FIG. 2. A first lumen 30extends from a first port 32 at proximal end 26 to a first opening 34proximal to occlusion balloon 28. A second lumen 38 extends from asecond port 40 at proximal end 26 to a second opening 42 proximal toocclusion balloon 28. The positions of first and second openings 34, 42are selected such that the openings will be disposed within theascending aorta downstream of the aortic valve when occlusion balloon 28is disposed between the brachiocephalic artery and the coronaryarteries, as described more fully below. First and second openings 34,42are preferably positioned within about 1 cm from the proximal end ofocclusion balloon 28. A pressure monitoring device may be connected tosecond port 40 for monitoring pressure in the aortic root through secondlumen 38.

First lumen 30 and first opening 34 are dimensioned to allowcardioplegic fluid to be delivered at sufficient rates to inducecardioplegic arrest effectively and rapidly. Usually, first lumen 30will be configured for delivery of a cardioplegic fluid containingblood, which has been shown to more effectively protect the myocardiumwhile the heart is arrested. In such cases, it is important that firstlumen 30 allow the cardioplegic fluid to be delivered at sufficientrates to rapidly flow from the aortic root into the coronaries, perfusethe myocardium, and arrest the heart, without requiring the fluid to bedelivered at excessive pressures which could damage the blood cellscontained in the fluid. Preferably, first lumen 30 will permit deliveryof cardioplegic fluid at rates of at least about 150 ml/min and atpressures no more than about 350 mmHg. Thus, first lumen 30 usually hasa transverse cross-sectional area of about 2.0-3.0 mm², and preferablyabout 2.4-2.8 mm² between first port 32 and first opening 34.

A third lumen 44 extends from a third port 46 to a third opening 48distal to occlusion balloon 28, usually being at distal end 24 of shaft22. As shown in FIG. 1, occlusion balloon 28 may be configured to extendbeyond the distal end of shaft 22 in an inflated configuration, butincludes a central passage 49 communicating with third opening 48 suchthat third opening 48 communicates with the aortic lumen distally of theocclusion balloon. Third lumen 44 is usually configured to deliveroxygenated blood into the aorta at rates sufficient to sustain thepatient on full cardiopulmonary bypass with the heart stopped, withoutreaching such high pressures as to cause excessive hemolysis, preferablyallowing blood flow rates of at least about 4 liters/min at pressures nohigher than about 350 mmHg. Third lumen 44 therefore has across-sectional area of at least about 20 mm², and preferably about30-60 mm², between third port 46 and third opening 48, although thenecessary cross-sectional area will vary depending upon the length ofthe catheter. Alternatively, as described more fully below, a separatearterial return cannula may be placed in an artery downstream ofocclusion balloon 28 to return oxygenated blood to the patient insteadof or as a supplement to arterial return through third lumen 44, inwhich case third lumen 44 may have a cross-sectional area that issignificantly smaller.

An inflation lumen 50 extends from an inflation port 52 to an inflationopening 54 disposed within the interior of occlusion balloon 28. Asource of inflation fluid, such as saline (preferably mixed with aradiopaque contrast agent) may be delivered through inflation lumen 50into the interior of occlusion balloon 28 to inflate the balloon.

Preferably, occlusion balloon 28 is a compliant, elastic material suchas silicone, urethane, or latex and is bonded to shaft 22 by adhesive,thermal, or solvent bonding. Occlusion balloon 28 is configured toexpand to a size sufficient to engage the inner wall of the aorta andfully occlude the aortic lumen to block blood flow through it. Thecompliance of the balloon allows it to be expanded to a range ofdiameters so as to occlude aortas of various size, usually beinginflatable to an outer diameter of at least about 20 mm and preferablyabout 20-40 mm for adult patients. Occlusion balloon 28 has an axiallength (parallel to the longitudinal axis of shaft 22) short enough toallow it to occlude the ascending aorta without blocking either thebrachiocephalic artery or the coronary arteries, preferably having alength in a range of about 20-50 mm for adult patients.

FIGS. 3A-3B illustrate the cardioplegia catheter of FIGS. 1-2 in use ina patient's heart. With occlusion balloon 28 positioned in the ascendingaorta AA between brachiocephalic artery BA and coronary arteries CA,shaft 22 extends through aortic valve AV, left ventricle LV, mitralvalve MV and a puncture P in the wall of left atrium LA. Preferably,shaft 22 extends out of the patient's chest through a percutaneousincision, trocar sleeve or other small access port (not shown) placed inan intercostal space between the ribs, without creating a mediansternotomy or other type of gross thoracotomy.

Once the cardioplegia catheter is positioned as shown, the patient maybe placed on cardiopulmonary bypass, whereby blood is withdrawn from avein through venous cannula 51, directed via venous line 53 to anextracorporeal cardiopulmonary bypass system 55 for oxygenation, andpumped via arterial return line 57 back into the aorta through thirdport 46, third lumen 44 and third opening 48. Preferably, venous cannula51 extends transluminally from a femoral vein FV through the inferiorvena cava and into the right atrium to remove blood from the heart.Cardiopulmonary bypass system 55 may be of known construction, includinga pump for applying negative pressure to venous cannula 51, anoxygenator for oxygenating the withdrawn blood, a bubble trap forremoving air bubbles from the blood, and an additional pump forreturning the blood to the arterial system. Other components andfeatures of cardiopulmonary bypass systems that may be employed in thesystem of the present invention will be apparent to those of skill inthe art.

Occlusion balloon 28 may then be inflated to occlude ascending aorta AA,and cardioplegic fluid may be delivered from a pressurized fluid source59 through first port 32, first lumen 30 and first opening 34 to perfusethe myocardium via coronary arteries CA, thereby arresting cardiacfunction. Preferably, cardioplegic fluid source 59 is configured todeliver a cardioplegic fluid comprising blood plus a cardioplegic agentsuch as potassium chloride, which has been found to optimally protectand preserve the myocardium during the procedure. Pressure in the aorticroot may be monitored through second lumen 38 and second opening 42,which are connected to a pressure monitoring system 61 outside thepatient's body. Venting of the aortic root proximally of balloon 28 maybe accomplished by turning a valve 63 so that first lumen 30 is incommunication with blood filtering and recovery module 65 instead ofcardioplegic fluid source 59. Blood, fluids and any embolized materialsremoved from the aorta are filtered by module 65 and the filtered bloodis returned to the body via cardiopulmonary bypass system 55.

In an additional aspect of the invention, illustrated in FIG. 3B, apulmonary artery catheter 69 and a coronary sinus catheter 71 areutilized in conjunction with cardioplegia catheter 20. These cathetersmay be introduced transluminally into the heart from a peripheral veinsuch as internal jugular vein IV. Pulmonary artery catheter 69 isadvanced from right atrium RA through the tricuspid valve TV, rightventricle RV and pulmonary valve PV into the pulmonary artery P A. Thecatheter is connected at its proximal end to a pump or other fluidaspiration device. Any blood or fluids not removed by venous cannula 51that reach the pulmonary artery may be removed through pulmonary arterycatheter PV, thereby Ii keeping the heart adequately vented. Bloodremoved through pulmonary artery catheter 69 may be returned to bloodfilter/recovery module 65 for treatment and return to the body viacardiopulmonary bypass system 55. Other aspects of pulmonary arterycatheters suitable for use in conjunction with the present invention aredescribed in copending application No. 08/415,238, filed Mar. 30, 1995,now abandoned, which is incorporated herein by reference.

Coronary sinus catheter 71 is advanced from jugular vein JV and rightatrium RA into the coronary sinus CS, through which blood ordinarilydrains from the coronary arteries and veins into the right side of theheart. Coronary sinus catheter 71 preferably includes a main lumenextending through its length to an opening at its distal end, allowingcardioplegic fluids to be delivered from a pressurized fluid source 73to the myocardium in a retrograde manner via the coronary veins. Tofacilitate this process, coronary sinus catheter 71 preferably includesa balloon 75 at its distal tip configured to occlude the coronary sinusduring delivery of cardioplegic fluids. Balloon 75 is inflated bydelivery of a fluid such a saline from a syringe 77 or other suitableinflation device via an inflation lumen in communication with balloon75. In this way, cardioplegic fluid may delivered through the coronarysinus catheter 71 either in conjunction with cardioplegic fluid deliverythrough cardioplegia catheter 20, or as a substitute for deliverythrough cardioplegia catheter 20. Other aspects of coronary sinuscatheters suitable for use in conjunction with the present invention aredescribed in U.S. Pat. No. 5,558,644, which is incorporated herein byreference.

A preferred technique of positioning cardioplegia catheter 20 in theascending aorta is shown in FIGS. 4-6. In this technique, a purse-stringsuture 60 is placed in the left atrial wall W around the intended siteof catheter introduction, as shown in FIG. 4. Suture 60 may be placedusing well-known techniques, and is preferably placed usingthoracoscopic instruments introduced through small incisions, trocarsleeves or other intercostal access ports not requiring a grossthoracotomy. The left atrium may be accessed via access ports in the3rd, 4th or 5th intercostal spaces on the right lateral or rightanterior side of the chest. If desired, the heart may be repositionedwithin the chest to improve access using thoracoscopic retractioninstruments introduced through access ports between the ribs. Oncepurse-string suture 60 has been placed in wall W, a small incision orpuncture P is formed in wall W so as to be encircled by suture 60, and aflow-directed catheter 64, shown in FIG. 5, is inserted through punctureP. The free ends 62 of suture 60 may then be tensioned so as to form aseal between wall W and the outer wall of flow-directed catheter 64.Preferably, a suture tensioner 66 is used to maintain tension on sutureends 62, which may consist of a tube 62 a having an inner lumen 70through which ends 62 may be passed. Lumen 70 is dimensionedfrictionally engage suture ends 62 so as to maintain adequate tension onsuture S to create a hemostatic seal around catheter 64.

Once positioned in the left atrium LA, as shown in FIG. 5, flow-directedcatheter 64 is advanced through the mitral valve MV into left ventricleLV, and through aortic valve AV into the ascending aorta AA. To assistsuch positioning, flow-directed catheter 64 has an expandable member 66at its distal end which, when expanded, is carried by the flow of bloodthrough the heart into the ascending aorta. Expandable member 66 isusually a balloon that is inflated with fluid introduced through aninflation lumen (not shown in Figure 5) extending through theflow-directed catheter into the interior of the balloon. Expandableember 66 may be inflated in the left atrium LA, from which blood willcarry it through the mitral and aortic valves into the aorta.Flow-directed catheter also includes a guidewire lumen (not shown inFIG. 5) through which a guidewire 68 may be positioned either during orafter flow-directed catheter is positioned in ascending aorta AA. Guidewire 68 is advanced through flow-directed catheter 64 until its tip isin ascending aorta AA, and flow-directed catheter is then removed fromthe patient, leaving guidewire 68 in position in the heart. As theflow-directed catheter is removed from left atrial wall W, purse-stringsuture S is tensioned to maintain a hemostatic seal around guidewire 68.

As shown in FIG. 6, the proximal end of guidewire 68 is then placed inthird lumen 44 in cardioplegia catheter 22 outside the heart, andcardioplegia catheter 22 is slidably advanced over guidewire 68 throughpuncture P, mitral valve MV, and aortic valve AV into ascending aortaAA. Guidewire 68 is then removed from third lumen 44, leavingcardioplegia catheter 20 in the position of FIG. 3.

As an alternative to the use of a guidewire, cardioplegia catheter 20may be configured to be advanced into the ascending aorta AA directlyover flow-directed catheter 64, as shown in FIG. 7. In this embodiment,flow-directed catheter 64 need not have a guidewire lumen, allowing itto be smaller and more flexible. Once cardioplegia catheter 20 has beenslidably advanced over flow-directed catheter 64 into ascending aortaAA, expandable member 66 is deflated and the flow-directed catheter iswithdrawn from third lumen 44.

As may be seen in FIG. 3A shaft 22 of cardioplegia catheter 20 must beshapable into a curve of very small radius in order to extend throughboth the aortic valve A V and mitral valve MV, a distal portion of theshaft which extends through the aortic valve being at an angle of around100-170 degrees, preferably about 110 to 150 degrees, relative to theC<proximal portion of the shaft which extends through the mitral valve.Preferably, shaft 22 will be reinforced in at least the region of thiscurve with a wire winding (not shown) embedded in its outer wall toprevent the shaft from kinking. Suitable wire-wound shafts and methodsof manufacturing such shafts are described in copending application Ser.No. 08/664,716, filed Jun. 17, 1996, now issued as U.S. Pat. No.5,879,499, which is incorporated herein by reference.

In addition to wire winding or other form of reinforcement, shaft 22 maybe preshaped in a curve to facilitate positioning the catheter throughthe mitral and aortic valves. The preshaped portion of the shaft willpreferably be shaped such that a distal portion of the shaft is disposedat an angle of about 90-150 degrees relative to the proximal portion ofthe shaft. The curve will usually be disposed about 4-8 cm from thedistal end of shaft 22 for use in adult patients. When introducingcardioplegia catheter 20 through puncture P, a stylet (not shown) may bypositioned in third lumen 44 to straighten the preshaped portion. Thestylet is gradually withdrawn from the catheter as it is advancedthrough the mitral valve into the left ventricle.

As another alternative, cardioplegia catheter 20 may have a generallystraight shaft 22, but a steerable or shapable stylet may be providedwhich is removably positionable in first lumen 30 or third lumen 44. Ina shapable embodiment, the stylet is a malleable material which permitsit to be inelastically shaped into the desired configuration, thenplaced into a lumen in shaft 22 to impart such shape to the shaft. Oncedistal end 24 of cardioplegia catheter 20 has been placed through themitral valve, the shaped stylet may be placed in either of lumens 30 or44 to orient distal end 24 in a suitable position for advancementthrough the aortic valve. In a steerable embodiment, the stylet includesa steering mechanism such as one or more pull wires extending through alumen in the stylet and fastened to its distal end, offset from theradial center of the stylet. By exerting tension on the pull wires, thedistal end of the stylet may be deflected into a curved or bent shape.In this way, once cardioplegia catheter 20 has been advanced through themitral valve, the stylet may be inserted in lumen 44 and deflected so asto re-orient distal end 24 of shaft 22 in a suitable orientation foradvancement through the aortic valve.

As a further alternative, cardioplegia catheter 20 itself may include asteering mechanism for steering the distal end of shaft 22 through themitral and aortic valves. For example, one or more pull wires may extendthrough a lumen in shaft 22 and be fastened near distal end 24, offsetfrom the radial center of the shaft. By tensioning the pull wires, thedistal portion of the shaft be deflected into a curved or bent shapesuitable for placement from the mitral valve through the aortic valve.

A second embodiment of a cardioplegia catheter 80 according to theinvention is illustrated in FIGS. 8-10. Cardioplegia catheter 80 is inmany respects similar to cardioplegia catheter 20 of FIGS. 1-7, having aflexible shaft 82, an occlusion member 84 at the distal end of shaft 82,a first lumen 86 extending from a first port 88 to a first opening 90proximal to occlusion member 94, a second lumen 92 extending from asecond port 94 to second opening 96 proximal to occlusion member 84, anda third lumen 98 extending from a third port 100 to a third opening 102distal to occlusion member 84. Occlusion member 84 is preferably anocclusion balloon, inflated by means of inflation fluid deliveredthrough an inflation lumen 104 extending from an inflation port 106 toan inflation opening 108 within the occlusion balloon.

Unlike the previous embodiment, cardioplegia catheter 80 furtherincludes a ventricular balloon 110 spaced proximally from occlusionmember 84 and first and second openings 90,94. The position ofventricular balloon 110 on shaft 82 is selected such that it will bedisposed in the left ventricle adjacent the aortic valve when occlusionballoon 84 is in the ascending aorta between the brachiocephalic arteryand the coronary arteries, usually being positioned about 4-8 cmproximally of occlusion balloon 84 for use in adult patients.Ventricular balloon 110 is inflated via a second inflation lumen 112extending from a second 25 inflation port 114 at the proximal end of theshaft to a second inflation opening 116 in shaft 82 within theventricular balloon. The balloon will preferably be inflatable to adiameter of about 2-4 cm to facilitate occlusion of the ventricularoutflow tract at the around the annulus of the aortic valve.

Cardioplegia catheter 80 of FIGS. 8-9 is shown in position in apatient's heart in FIG. 10. The catheter may be introduced from apuncture P in the left atrium LA, through the mitral valve MV, leftventricle LV, and aortic valve AV in the manner described above inconnection with FIGS. 4-7. When ventricular balloon 110 is positioned inthe left ventricle LV, it may be inflated so as to prevent furtheradvancement of cardioplegia catheter 80 into the aorta. Ventricularballoon 110 is seated within the left ventricular outflow tract inengagement with the ventricular wall around the annulus of the aorticvalve. With cardiopulmonary bypass established and oxygenated bloodbeing returned to the arterial Li system via third lumen 98 or through aseparate arterial cannula, occlusion balloon 84 is expanded to occludethe ascending aorta AA, preventing arterial blood from reaching thecoronary arteries CA. Cardioplegic fluid is then delivered through firstlumen 86 into the aorta proximal to occlusion balloon 84, from which thefluid may flow into the coronary arteries to perfuse the myocardium andarrest the heart. It may be seen that, with shaft 82 extending throughaortic valve AV, some cardioplegic fluid could flow around shaft 82through the aortic valve leaflets into the left ventricle LV.Advantageously, ventricular balloon 110 occludes the left ventricularoutflow tract around the aortic valve annulus, preventing flow of fluidinto the left ventricle.

The invention provides a number of different alternatives for returningoxygenated blood to the patient's arterial system downstream from theocclusion member of the cardioplegia catheter. In one embodiment,described above, oxygenated blood is returned to the aorta through thirdlumen 44 in cardioplegia catheter 20 or third lumen 98 in cardioplegiacatheter 80. This has the advantage of eliminating the need for aseparate arterial cannula and the associated arterial incision throughwhich the cannula would be placed. However, in some cases, it may bedesirable to decouple the arterial return device from the cardioplegiacatheter so that if the need arises to remove the occlusion member fromthe ascending aorta, it can be rapidly removed without removing thearterial cannula, which would require the patient to be weaned fromcardiopulmonary bypass. To provide this advantage, a separate arterialcannula may be used in addition to or instead of the third lumen in thecardioplegia catheter.

In one embodiment, shown in FIG. 11, an arterial return cannula 120 isslidably positioned through third lumen 44 in cardioplegia catheter 20.Arterial return cannula 120 is configured to deliver oxygenated bloodinto the aorta at rates sufficient to sustain the patient on fullcardiopulmonary bypass with cardioplegic arrest, having a blood flowlumen and one or more outlets 122 at its distal end 124 with dimensionssimilar to those described above in connection with third lumen 44 ofthe cardioplegia catheter. In use, cardioplegia catheter 20 is firstpositioned in the ascending aorta in the manner described above.Arterial return cannula 120 is then slidably advanced through thirdlumen 44 until distal end 122 is positioned in ascending aorta AA.Arterial return cannula 120 is connected at its proximal end to theextracorporeal cardiopulmonary bypass circuit so as to receiveoxygenated blood and deliver it into the aorta. Occlusion balloon 28 maythen be inflated to occlude the ascending aorta, and cardioplegic fluiddelivered through first lumen 30 to arrest the heart. Should the needarise to remove occlusion balloon 28 from the aorta during theprocedure, occlusion balloon 28 is deflated, and cardioplegia catheter20 slidably retracted over arterial cannula 120, which may continue todeliver blood into the arterial system. In an alternative embodiment,shown in FIG. 12, an arterial return cannula 130 is configured forintroduction in a femoral or iliac artery. Arterial return cannula 130may be short, e.g. 4-10 cm, so as to extend only into the iliac orabdominal aorta, but is preferably at least about 80 cm long so as toextend into the thoracic aorta or aortic arch as shown. In this way,blood may be returned to the aorta near the vessels at the top of thearch that deliver blood to the head and neck, and allowing blood to flowin the natural, antegrade direction through the aorta, iliac and femoralarteries. Arterial return cannula 130 is again 3 configured to deliverblood at sufficient rates to support the patient on full cardiopulmonarybypass with the heart arrested, delivering flows of at least about 4liters/min at pressures no higher than 350 mmHg. Arterial return cannula130 has an inner lumen and outlets 132 at its distal end 134 withdimensions sufficient to provide such flows. At the same time, arterialreturn cannula 130 has outer dimension small enough to be positionablein a femoral artery of limited diameter. Usually, arterial returncannula 130 has an inner lumen with cross-sectional area of at leastabout 30 mm², preferably about 40-70 mm² ₁ and an outer diameter of nomore than about 8 mm, preferably about 6-7 mm, for use in adultpatients. Of course, if oxygenated blood is also returned through thirdlumen 44 of cardioplegia catheter 20, arterial return cannula 130 mayhave a smaller lumen.

In a further embodiment, illustrated in FIG. 13, an arterial returncannula 140 is configured for placement in a subclavian or axillaryartery and advanced into or near the aortic arch. In this way, arterialblood may be returned to the aorta near the top of the aortic arch so asto flow in an antegrade direction. Arterial return cannula has an innerlumen in communication with one or more openings 142 near its distal end144, and preferably has a length of about 10-50 cm, an outer diameter ofabout 6-7 mm, and an inner lumen with cross-sectional area of about30-50 mm² to deliver oxygenated blood at sufficient rates to sustain thepatient on full cardiopulmonary bypass.

In another embodiment, shown in FIG. 14, an arterial return cannula 150is configured to be placed thoracoscopically into the ascending aortathrough an aortic puncture AP. Blood leakage through aortic puncture APmay be avoided by placing a purse-string suture (not shown) around thepuncture similar to suture S placed in the left atrial wall, asdescribed above in connection with FIG. 7. Arterial return cannula 150is configured to direct oxygenated blood in a downstream direction inthe aorta, having an inner lumen communicating with at least one outlet152 at its distal end 154. The inner lumen of arterial return cannula150 has a cross-sectional area of about 30-50 mm² so as to deliver bloodat sufficient flows to maintain full cardiopulmonary bypass with theheart stopped. Arterial return cannula 150 further has a length of atleast about 20 cm so as to extend out of the chest through a smallincision, trocar sleeve, or access port in an intercostal space, withoutcreating a gross thoracotomy.

An additional embodiment of a cardioplegia catheter system according tothe invention is shown in FIGS. 15-17. In this embodiment, cardioplegiacatheter system 160 includes an arterial return cannula 162 having areturn lumen 164, a return opening 166 at its distal end and a returnport 168 at its proximal end. A catheter port 170 is in communicationwith return lumen 164 at the proximal end of arterial cannula 162 andincludes a hemostasis valve 172 for sealing around a catheter shaftpositioned in the catheter port. Hemostasis valve 172 may be any of avariety of well known types, comprising, for example, a pair of parallelcompliant elastomeric disks 174, 176, one having an axial slit (notshown) for sealing when the catheter shaft is absent, and one having around axial hole (not shown) for sealing around the catheter shaft.Return port 168 includes a hose barb 178 for connection to standardtubing from an extracorporeal cardiopulmonary bypass circuit to receiveoxygenated blood. A seal 179, which may be an elastomeric O-ring, ismounted near return opening 166 for sealing around a catheter shaftpositioned therethrough.

A cardioplegia catheter 180 is slidably positionably positionablethrough catheter port 170, return lumen 164 and return opening 166.Cardioplegia catheter 180 has a multilumen shaft 182 and a balloon 184mounted near its distal end configured to occlude the ascending aorta.Shaft 182 includes a first lumen 186 extending from a first opening 188just proximal to balloon 184 to a first port (not shown) at the proximalend of the shaft. A pressure lumen 190 extends from a pressure opening192 just proximal to balloon 184 to a pressure port (not shown) at theproximal end of the shaft. An inflation lumen 194 extends from aninflation opening 196 within balloon 184 to an inflation port (notshown) at the proximal end of the shaft.

A blood lumen 198 extends from a blood outlet 200 at the distal end ofshaft 182 to a plurality of blood inlets 202 in the sidewall of shaft182 in a proximal region thereof. Blood inlets 202 are positioned so asto be within return lumen 164 when balloon 184, first opening 188 andpressure opening 192 are disposed distally of the distal end of arterialreturn cannula 162. In this way, blood flowing through return lumen 164flows into blood inlets 202 and through blood lumen 198 into the aortadistally of balloon 184. Blood lumen 198 is preferably configured toprovide sufficient blood flow for full cardiopulmonary bypass withcardioplegic arrest, dimensioned to provide flows of at least 4liters/min at pressures not exceeding 350 mmHg.

The positioning of cardioplegia catheter system 160 in the heart andascending aorta is illustrated in FIG. 17. Usually, cardioplegiacatheter 180 will first be positioned in arterial return cannula 162 andthe two will placed through a penetration P in the left atrium LA(sealed by a purse-string suture), advanced through the mitral valve MV,through the aortic valve AV, and into the ascending aorta AA. A guidewire, stylet, or flow-directed catheter may be used to assist placement,as described above. Arterial blood flow is initiated through return port168, from which the blood flows through blood lumen 198 and blood outlet200 into the aorta. Balloon 184 is then inflated so as to occludeascending aorta AA. A cardioplegic agent may then be delivered throughfirst lumen 186 and first opening 188 so as to arrest the heart.

When it is desired to remove cardioplegia catheter 180 from theascending aorta, it may be slidably withdrawn from return lumen 164while arterial return cannula 162 remains in place, at which time bloodflowing into return port 168 will flow directly through return lumen 164into the aorta, thereby continuing to maintain circulation of oxygenatedblood in the patient.

It should be understood that as an alternative to the embodimentillustrated, a single blood inlet port in communication with blood lumen198 at the proximal end of cardioplegia catheter 180 may be provided inplace of blood inlets 202. The oxygenated blood return line may beconnected both to this blood inlet port and to return port 168 of thearterial cannula, preferably in series with a two-way valve to allowselective direction of blood flow between either port. In this way, whencardioplegia catheter 180 is positioned in return lumen 164, blood maybe directed to the blood inlet port at its proximal end so as to flowinto the aorta distally of balloon 184. When the cardioplegia catheteris removed, blood may be directed to flow through return port 168 tocontinue flow into the aorta through arterial return cannula 160.

FIG. 18 illustrates still another embodiment of a cardioplegia cathetersystem according to the invention. Cardioplegia catheter system 210includes a tubular sheath 212 having distal end 214 configured forplacement through a penetration P in the left atrium LA. Sheath 212 hasan opening 216 at its distal end 214 and first and second ports 218, 220at its proximal end, each of which preferably has a hemostasis valve(not shown) for sealing around a catheter shaft positioned therethrough.An arterial return cannula 222 is slidably positionable through firstport 214 and sheath 212 and has a distal end 224 which may be advancedinto the ascending aorta AA through mitral valve MV and aortic valve AV.Arterial return cannula 222 has a return opening 226 at its distal end,a return port 228 at its proximal end, and a return lumen (not shown)therebetween through which oxygenated blood may be delivered into theaorta.

Cardioplegia cannula 230 may be constructed similarly to cardioplegiacannula 20 described above in connection with FIGS. 1-3, having aballoon 232 for occluding the ascending aorta, a cardioplegia/ventingopening 234 and pressure opening 236 proximal to balloon 232, and aninflation opening 238 within balloon 232, along with associated lumensand proximal ports 240, 242, 244 in communication with openings 234,236, 238, respectively. A distal opening 246 and corresponding lumen areoptionally provided to assist placement of the cardioplegia cannula overa guidewire or flow-directed catheter.

After arterial return cannula 222 has been positioned through sheath 212and advanced into ascending aorta AA, cardioplegia catheter 230 isslidably introduced through second port 220 in sheath 212 and advancedthrough the heart into the ascending aorta AA. Balloon 232 is theninflated to occlude the ascending aorta AA between the brachiocephalicartery BA and coronary arteries CA, with distal end 224 of arterialreturn cannula 222 extending distally of balloon 232 to maintain flow ofoxygenated blood into the arterial system. The compliance of balloon 232allows it to conform around the shaft of the arterial return cannula tofully occlude the ascending aorta. Should cardioplegia catheter 230 needto be removed, balloon 232 is simply deflated and the catheter isretracted from sheath 212, with arterial return maintained by arterialreturn cannula 222.

While the above is a complete description of the preferred embodimentsof the invention, various alternatives, modifications, substitutions andequivalents may be used without departing from the scope of theinvention, which is defined by the appended claims.

1. A cardioplegia catheter for inducing cardioplegic arrest comprising:shaft with a distal end, a proximal end, an opening near the distal end,a port at the proximal end, and an inner lumen fluidly connecting theport and the opening, a distal portion of the shaft being configured toextend into the ascending aorta when a proximal portion of the shaftextends into a left chamber of the heart though the aortic valve and outof the heart through a penetration in a wall thereof; an occlusionmember mounted to the shaft distally of the opening and configured toocclude the ascending aorta between the brachiocephalic a and thecoronary ostia; and a sealing device for sealing the penetration in thewall of the heart around the shaft to inhibit blood flow therethroughwherein the sealing device comprises a purse string suture applicable tothe wall of the heart around the penetration.
 2. The cardioplegiacatheter of claim 1 wherein the shaft is between about 25 cm and 75 cmin length.
 3. The cardioplegia catheter of claim 1 further comprising asource of cardioplegic fluid in communication with the port at theproximal end of the shaft.
 4. The cardioplegia catheter of claim 1wherein the inner lumen is configured to deliver cardioplegic fluid at arate of at least about 150 ml/min and a pressure less than about 350mmHg.
 5. The cardioplegia catheter of claim 1 wherein the inner lumenhas a cross-sectional area of at least about 2.2 mm² between the portand the opening.
 6. The cardioplegia catheter of claim 1 furthercomprising a delivery opening distal to the occlusion member, a deliveryport at the proximal end of the shaft, and a delivery lumen extendingbetween the delivery port and the delivery opening.
 7. The cardioplegiacatheter of claim, 6 wherein the delivery lumen is configured to deliverblood at sufficient rates to maintain the patient under fullcardiopulmonary bypass with cardioplegic arrest.
 8. The cardioplegiacatheter of claim 7 wherein the delivery lumen is configured to deliverblood at a rate of at least about 4 liters/min at a pressure no morethan about 350 mmHg.
 9. A cardioplegia catheter, comprising: a shaftwith a distal end, a proximal end, an opening near the distal end a portat the proximal end, and an inner lumen fluidly connecting the port andthe opening, a distal portion of the shaft being configured to extendinto the ascending aorta when a proximal portion of the shaft extendsinto a left chamber of the heart through the aortic valve and out of theheart through a penetration in a wall thereof; an occlusion membermounted to the shaft distally of the opening and configured to occludethe ascending aorta between the brachiocephalic artery and the coronaryostia; a guiding device for guiding the distal end of the shaft into theascending aorta with the proximal end extending through a leftventricle, a mitral valve and a left atrium of the heart and a sealingdevice for sealing the penetration in the wall of the heart around theshaft to inhibit blood flow therethrough, wherein the sealing devicecomprises a purse string suture applicable to the wall of the heartaround the penetration.
 10. The cardioplegia catheter of claim 9 whereinthe guiding device comprise a guidewire positionable in the ascendingaorta from the left chamber of the heart.
 11. The cardioplegia catheterof claim 9 wherein the guiding device comprises a flow directed catheterpositionable through a lumen in the shaft and having an expandablemember at a distal end thereof for being carried by blood flow into theascending aorta.
 12. A cardioplegia catheter, comprising: a shaft with adistal end, a proximal end, an opening near the distal end, a port atthe proximal end, and an inner lumen fluidly connecting the port and theopening, a distal portion of the shaft being configured to extend intothe ascending aorta when a proximal portion of the shaft extends into aleft chamber of the heart through the aortic valve and out of the heartthrough a penetration in a wall thereof; an occlusion member mounted tothe shaft distally of the opening and configured to occlude theascending aorta between the brachiocephalic artery and the coronaryostia; a pressure monitoring device coupled to the shaft far monitoringpressure in the ascending aorta proximal to the occlusion member and asealing device for sealing the penetration in the wall of the heartaround the shaft to inhibit blood flow therethrough, wherein the sealingdevice comprises a purse string suture applicable to the wall of theheart around the penetration.
 13. The cardioplegia catheter of claim 12further comprising a pressure opening in the shaft proximal to theocclusion member, a pressure port at the proximal end of the shaft, anda pressure lumen extending between the pressure port and the pressureopening, the pressure monitoring device being in communication with thepressure port at the proximal end of the shaft.
 14. A catheter systemfor inducing cardioplegic arrest comprising: a cardioplegia catheterincluding: a shaft with a distal end, a proximal end, an opening at thedistal end, a port at the proximal end, and an inner lumen fluidlyconnecting the port and the opening, a distal portion of the shaft beingconfigured to extend into the ascending aorta when a proximal portion ofthe shaft extends into a left chamber of the heart through the aorticvalve and out of the heart through a penetration in a wall thereof; andan occlusion member mounted near the distal end of the shaft andconfigured to occlude the ascending aorta between the brachiocephalicartery and the coronary ostia; a source of cardioplegic fluid incommunication with the port at the proximal end of the shaft; anarterial return cannula positionable in an artery downstream of theocclusion member for maintaining circulation of oxygenated blood in thepatient's arterial system; and a sealing device for sealing thepenetration in the wall of the heart around the shaft to inhibit bloodflow therethrough wherein the sealing device comprises a purse stringsuture applicable to the wall of the heart around the penetration.